VirusZ made by Georg Hörmann (Amiga) - Virus Help Team


VirusZ III 1.02 Documentation
Copyright © 2002-2004 by Georg Hörmann


The VirusZ software package is FREEWARE and copyright © 1991-1999/2002-2004 by Georg Hörmann and © 1999-2001 by Dirk Stöcker. The installation script is © by David Crawford and the MorphOS icon is © by Christian Rosentreter.

No parts of this package may be altered by any means (this includes editing, reprogramming, crunching, resourcing etc.), except archiving. The author is in no way liable for any changes made to any part of the package, or consequences thereof as he is in no way liable for damages or loss of data directly or indirectly caused by this software.

Neither fees may be charged nor profits may be made by distributing this software package. Outside a single machine environment, you are not allowed to reproduce single parts of the package, but you have to copy it completely.


For any comments, bug reports, snapshots or if you have found a new virus, contact the author at the following addresses:

Georg Hörmann
Martinswinkelstraße 16c
82467 Garmisch-Partenkirchen


You will always find the latest updates of VirusZ and related files in the Aminet (util/virus) or at the following places:

Virus Help Team Denmark homepage :
Dirk Stöcker's homepage :


VirusZ will run on any (emulated or real) Amiga that comes with at least AmigaOS 2.04 (Kickstart v37) or MorphOS. The following disk-based libraries are required:

- commodities.library v37+ (part of AmigaOS)
- rexxsyslib.library v33+ (part of AmigaOS, for ARexx features)
- reqtools.library v38+
- xfdmaster.library v37+
- xvs.library v33+
- xadmaster.library v8+ (optional, for scanning inside archives)
- disassembler.library v40+ (optional, for disassembling bootblocks/memory)

None of these libraries will be distributed with the VirusZ package any longer (because of copyright reasons and the exploding size of the archive), get them from Aminet or the homepages mentioned above.


Installation requires nothing more than either clicking on the install icon or dragging VirusZ to your WBStartup drawer by hand or adding the following line to your 'S:User-Startup' file:

[Path]VirusZ [Option(s)]

To make sure that you have received an original version of VirusZ and not a fake, you can use my PGP key added at the end of this documentation together with the signatures included in the archive to verify the files. You can also download a 100% safe copy of my PGP key from the homepages mentioned above.

Additionally, you should compare the file size of your VirusZ copy with the one displayed in the 'About' information. They MUST match if you didn't crunch VirusZ with a file compressor.


VirusZ might crash if both disassembler.library and mmu.library exist in your LIBS: drawer, but the mmu.library setup is incorrect. In those cases, either configure your mmu.library environment correctly (read the manuals) or delete/rename mmu.library, so that disassembler.library cannot find it at startup. Thanks to Harry Sintonen for this report.

Sometimes when a device gets Inhibit()ed by the sector check, the filesystem in ROM causes a hit. It then releases less memory than it has allocated. This is not a bug in VirusZ!

These device drivers cannot handle NSD-commands correctly and crashed with pre-1.00 releases of VirusZ. Due to a changed behaviour of VirusZ since v1.00, there shouldn't be any more problems.


VirusZ currently supports the following Shell template:


For more detailed information about Shell syntax, commodity usage and hotkey definitions, please consult the manuals shipped with your Amiga.

Please note that the ARexx interface commands described below require VirusZ to be active already. If it is not, it will first be started, the starter process will wait until the ARexx port appears and then the commands are sent to the port.

Specifies the commodity priority of VirusZ's broker. Values may range from -128 to 127, default is 0.

Defines the hotkey used to pop up the main window.

Tells VirusZ whether to pop up on startup or not.

Tells VirusZ to open its windows on the defined public screen instead of the Workbench screen.

The argument given to this option will be directly sent to VirusZ's ARexx port as a command and the return code in the Shell will correspond to the return code of the ARexx command.

Sends the ARexx command "QUIT" to an already running copy of VirusZ and thus terminates it.


For more detailed information about tooltypes, commodity usage and hotkey definitions, please consult the manuals shipped with your Amiga.

VirusZ currently supports the following tooltypes:

Specifies the commodity priority of VirusZ's broker. Values may range from -128 to 127, default is 0.

CX_POPKEY: Defines the hotkey used to pop up the main window. CX_POPUP:
Tells VirusZ whether to pop up on startup or not.

Tells VirusZ to open its windows on the defined public screen instead of the Workbench.


VirusZ has an ARexx port called 'VIRUSZ_III.REXX' that currently offers the following commands:

This command makes VirusZ close its main window and work in the background. To get the interface back you have to use the defined hotkey or the Exchange utility.

This command terminates VirusZ.

As you can see, there are no really useful commands implemented at the moment that can help you with virus scanning. This only might change in the near future if *YOU* have any suggestions...


VirusZ will perform a system scan at startup-time and afterwards survey your computer for suspicious activities. You can tell VirusZ what exactly should happen on startup via the 'Startup' preferences and control the surveillance mode via the 'Surveillance' preferences.

The following options appear in the 'Startup' preferences only:

'Perform Self-Test':
If enabled, the hunk structure of VirusZ will be checked. An alert appears if there is something wrong (might be a link virus). Disable this option if you intend to crunch VirusZ with a file packer because most of them modify the hunks.

'Load Bootblock Brain':
If this option is enabled, the default bootblock brain (see 'Bootblock Lab' preferences) will be loaded automatically.

'Pop Up Main Window':
If enabled, VirusZ opens the main window, otherwise it can be controlled via the Exchange commodity or the ARexx port only.

'Activate Main Window':
This option tells VirusZ to activate the main window. This is useful for all users that don't have VirusZ running in the background all the time and want to start a scan without activating the window by hand first.

The following options appear in both the 'Startup' and the 'Surveillance' preferences (introduced by 'Check...' or 'Survey...'):

System pointers used by viruses (but also by useful utilities) to keep their code reset resistant. Only disable these options if you really know what you are doing.

'...CPU Interrupts/Exec Interrupts/Library Vectors/Process Fields':
Other system pointers often used by viruses. Please note that also lots of harmless utilities use them, not every alert that VirusZ will send you means there's a new virus in your system.

This will scan the bootblocks of all available disks, newly inserted disks are detected if surveillance is activated.

Scans all disk-validator files found in L: drawer of any inserted disk.


VirusZ uses the standard AmigaOS method to store/save preferences. Therefore the drawer 'VirusZ_III' will be created in your ENVARC: and ENV: drawers. You can save the current settings, restore or load settings with the corresponding menu items in the 'Preferences' menu of VirusZ.

Additionally, whenever you save your preferences, the positions and sizes of all VirusZ windows will be stored/saved too. This means that you can arrange all windows just as you like them, they will appear in the same positions the next time you start VirusZ.

Settings that affect either VirusZ in general or influence several functions can be found in 'Miscellaneous' preferences:

'Requesters Follow Mouse':
If enabled, all ReqTools requesters appear with the negative response under the mouse pointer. If disabled, they pop up in the top left corner.

'Close Main Window = Exit':
If enabled, VirusZ quits when you click on the close-window button of the main window, otherwise it will act as if you selected the 'Hide' item from the 'Project' menu.

'Quit Immediately':
If enabled, VirusZ quits without verification.

'Report Known Bootblocks':
Usually, bootblocks recognized by the brain are not reported (that's the main purpose of the whole brain system). But it may sometimes be useful to get those already known bootblocks reported anyway. If this option is enabled, that's excactly what will happen.

'Install SnoopDos Task':
If enabled, a task called 'SnoopDos' will be created which doesn't use any CPU time, but prevents several trojans from doing any harm.

'Center Main Window':
If enabled, VirusZ's main window appears centered at the top border of the screen. Otherwise it will use the coordinates that have been last saved.

'Center Other Windows':
If enabled, all VirusZ windows appear centered on the screen. Otherwise they will use the coordinates that have been last saved.

'Use Disassembler.Library':
If disabled, both 'Bootblock Lab' and 'Memory Monitor' will not try to open that library. VirusZ obviously can't show you any assembler instructions in this case, but will need less memory and avoids the mmu.library from being loaded automatically by disassembler.library.

The default commodity hotkey used to pop up the main window.


Whenever you select files or sectors for checking (see below), there happens nothing more but a corresponding job gets added to the internal joblist. As soon as there is at least one job in this list, the 'Job Monitor' opens and the (first) job gets processed.

Please note that VirusZ has a fully asynchronous design, which means you can select new files/sectors even while others still get checked. The jobs will all be linked to the joblist and be processed one after the other. You can also delete/disinfect malicious files while the job is still running.

The status line is the topmost part of the 'Job Monitor'. Here you can see which file or sector gets checked at the moment. It therefore also is some kind of progress indicator.

Whenever there's something to be reported (virus/error/encoded file), this happens in the report list in the middle. By selecting an item, more information about this item appears below in the three info lines. You can select the 'Statistics' during a check and they will be updated after every checked file/sector. This is actually not recommended all the time, because it may slow down checking. 'Jobs' will be displayed only until they have finished and then disappear.

The gadgets at the bottom have the following functions:

This cycle gadget simply pauses/runs the current job. But please note that it's not necessary to pause a running job in order to delete/disinfect files or sectors!

'Check Files...':
Same function as the equally named item in VirusZ's main menu, just easier to reach if you want to check some more files.

Only enabled if you have either selected a file infected by a linkvirus or a repairable disk-sector from the report list. In case of an infected file, this function may repair just the selected file or all infected files (see below). For disk-sectors, repairing all of them at once is limited to sectors of the same disk.

This cycle gadget determines the functionality of 'Delete' and 'Disinfect'. If set to 'One', only the selected item will be treated, otherwise 'All' items of that type will be handed over to the corresponding function.

Only enabled if you have selected a delete-only malicious file from the report list. This function will either delete only the selected file or all malicious files that have been detected so far (see above).

'Kill Job':
Only enabled if you select a job from the report list. By clicking on this gadget, the job will be terminated immediately. Useful if you have selected wrong files for checking.

Closes the job monitor and removes *all* running/waiting jobs, so be careful with that if checking is not finished yet.


You can check files at any time by selecting the 'Check Files...' item from the 'Project' menu or clicking the equally named gadget in the 'Job Monitor' window (if it's currently opened). A filerequest will appear where you simply select the files to be checked.

The following settings can be adjusted in the 'File Check' preferences (they will be given away with every job at launch-time, so changing settings later doesn't have any effect on already running jobs):

'Skip Subdirectories':
Enable this option to skip drawers that may exist inside a selected drawer.

'Don't Ask For Passwords/Keys':
If enabled, every encrypted file/archive will be reported, but not (completely) analysed. Always switch on this option if you want to scan whole partitions and go for a coffee in the meantime. It is guaranteed that VirusZ will not ask for anything during a file check then.

'Decrunch Data Files':
If this option is enabled, the file check reads and decrunches data files in order to check them. This is useful for data files that actually contain executables, eg. XPK packed files.

'Extract File Archives':
If enabled, files inside file-archives get extracted and checked. This is very useful for checking software downloads quickly without any hand-work. While scanning inside archives, the archive name is marked with '<' and '>' in the status line. Xadmaster.library v8+ is required for this option!

'Extract Disk Archives':
If enabled, disk images from disk-archives get extracted. Please note that this option only tells VirusZ to extract such images. The contents however will only be checked if some of the following options are enabled too. Xadmaster.library v8+ is required for this option!

'Check Files Inside Disk Images':
If enabled, files embedded in disk images will be checked. Such images can be the result of extracted disk archives (see above) or just plain image files on your harddisk (eg. ADF files). While scanning inside a disk image, its name is marked with '[' and ']' in the status line. Note that xadmaster.library v8+ is required for this option!

'Scan Files For Bootblocks':
If enabled, files will be scanned for embedded bootblock viruses. This is especially helpful to detect new bb-virus installers or brainfiles of other antivirus programs.

'Don't Check Sectors In Files/Only Check Them In DOS Images/Check Them In Any Disk Image/Check Sectors In All Files':
Here you can tell VirusZ to perform a sector check inside the selected types of files. Please note that disk images are simply detected by their file size (must be a multiple of 512), so it might happen that other files with fitting sizes get checked too. The option 'Check Sectors In All Files' might slow down checking extremely as *all* files must be loaded completely, so it's not recommended for everyday use. Additionally, due to its nature, sector checking inside all kinds of files might lead to false recognitions in some very rare cases!

'Ignore External Xfd-Slaves/Only Use Them For Executables/Use All External Xfd-Slaves':
These options tell VirusZ which external slaves of xfdmaster.library should be used for decrunching files. You should always allow external slaves for executables to ensure that really all executables get decrunched, but if some badly coded third party slaves crash your system, you can switch them off completely.

'Ask Before Deleting Files':
If this option is enabled, pressing the 'Delete' button will not directly erase the selected file, but you will be prompted once again. Very helpful to avoid accidental loss of data. Please note that you cannot overrun the security request for deleting *all* malicious files with this option.


You can start checking disk sectors of trackdisk-like devices at any time by selecting 'Check Sectors...' from the 'Project' menu. A device selector will appear where you select the device to be checked. Use the 'Refresh' button to update the device list if you have mounted new devices lately.

This sector check only has the purpose to scan for sectors that have either been destroyed or modified by viruses. It doesn't verify your disks for any other failures like damaged filesystem blocks etc. Although it allows scanning of several kinds of devices (floppies, harddisks), it should only be used with standard 880k/1760k Amiga floppy disks! None of the viruses that modify sectors ever worked with third-party devices or on harddisks, so there's actually no need to scan them! Additionally, it might be dangerous to scan FFS disks as they have never been infected in the past, but might lead to false alarms in some rare cases. You have been warned!

The following settings can be adjusted in the 'Sector Check' preferences:

'Check DOS Disks Only':
This option should always be enabled. Only switch it off if you need to scan damaged Kickstart disks or similar trackdisk-based disks.


The bootblock lab offers all bootblock-related functions that are necessary to fight bootblock viruses and some more extras.

ATTENTION: Be careful with writing to / installing your harddisks. I'm not reliable for your faults.

There are two cycle gadgets in the bootblock lab, one on each side of the status line. The left one selects the device you want to work with, the right one selects the display mode (ascii dump, hex dump or disassembler mode if disassembler.library is installed).

Some words about the disassembler output:
The default output format of disassembler.library is not very usable for looking at bootblocks as it shows the 32-bit addresses where the bootblock is really located in memory and all pc-relative instructions point at those addresses too. So I decided to modify the output internally to 16-bit format with bootblock addresses from $0000 to $03ff. All pc-relative instructions appear that way, the ones pointing outside the bootblock range are marked as *-$0xxx or *+$0xxx, where * means either the start or the end of the bootblock. Locations outside a range of +/- 1kB around the bootblock nevertheless appear with their original 32-bit address.

Whenever there occurs any error, this will be displayed in the status line and hence the name of the currently buffered bootblock will be overwritten. By clicking on the 'Name' gadget, the name is printed once again.
Functions offered via the bootblock lab gadgets:

Reads the bootblock from the currently selected device to the buffer. Only DOS disks can be read.

Writes the current buffer contents to the bootblock of the selected device. The disk type and the checksum will be corrected automatically.

Installs either a default Kick 1.3, default OS 2.0 or uninstalled bootblock (see 'Bootblock Lab' preferences) to the currently selected device. The disk type will be corrected automatically.

Opens a file request to select a bootblock file that should be loaded to the buffer. Only DOS bootblocks can be loaded. You can use this function with ADF files and similar disk images too as only the bootblock will be loaded.

Saves the current buffer contents to a file. This is useful to create backups of important bootblocks (eg. games or other commercial software). NOTE: Do NOT try to write back a bootblock to an ADF file that way, your diskimage will be deleted!

This gadget will only be enabled if the bootblock in the buffer is neither a virus nor any other known bootblock. VirusZ will first ask for a name and then add the unknown bootblock to its brain. From now on, this bootblock will be reported with the given name and the background check will no longer report it as unknown.

Functions offered via the bootblock lab menus:

'Brain/New Brain':
Removes the currently loaded brain from memory.

'Brain/Load Brain':
Loads a new brain file from disk to memory.

'Brain/Save Brain':
Saves brain changes to file.

'Brain/Merge Brains':
Adds brain cells from a second file to the currently loaded brain.

'Brain/Edit Brain':
Here you can rename or delete brain cells.

'Misc/Refresh Devices':
VirusZ is unfortunately not able to detect devices that have been mounted after startup automatically. If you want to check such a device, you have to refresh the device list with this function.

The bootblock lab offers the following settings in the 'Bootblock Lab' preferences:

'Ask Before Write Access':
If enabled, a security request pops up every time you select 'Write' or 'Install' in the bootblock lab.

'Read Inserted Disks':
This enables the bootblock lab to read the bootblocks of inserted disks automatically. Useful if you intend to check a whole box of disks for bootblock viruses.

'Install Kick 1.3 Bootblock/...OS 2.0 Bootblock/...Non-Bootable BB':
Selects the type of bootblock that will be installed by the 'Install' function.

The path and filename of the default bootblock brain. This will be used in the file requests of the bootblock lab and for loading the brain at startup (see 'Startup' preferences).


Mostly all viruses work in the same manner. Either they make themselves resident and/or corrupt some libraries or devices with their code. Therefore the vector check was designed to help you finding new viruses that can't be recognized directly by the xvs.library yet.

It will display all system vectors that are not zero or do not point to standard ROM locations and tell you whether the changes are caused by utilities already known or by something unknown. But this will not necessarily mean that every vector marked 'SUSPICIOUS' is corrupted by a new virus, there are lots of system enhancers and other tools around that cause such changes.

You should nevertheless be alarmed if you are sure that you didn't have installed any programs that change vectors and suddenly something gets reported by VirusZ.

You might have installed a lot of patches that already get reported by name, and the output is awfully long, then you can disable the displaying of known patches in the 'Vector Check' preferences.

If the SegTracker utility (part of VirusZ's archive) has been installed to your system, you have the possibility to use its tracked information for the vector check output. Simply enable the respective option in the prefs and suspicious pointers will be handed over to SegTracker for identification. The program's name, hunk and offset will be reported if available.

You can select every single line of the vector check report. The following functions are available if they can be applied on the selected item:

Starts the memory monitor of VirusZ and supplies it with the address of the selected vector.

Creates a snapshot of an unknown vector and saves it automatically to the 'Snapshot Drawer' you have defined in the 'Vector Check' preferences. You can send me all your snapshots and I will add them to the vector check. IMPORTANT:
(a) Do not snapshot the same vectors several times, this causes me a lot of work just for nothing!
(b) Install and use SegTracker (see above) whenever possible! Only if it's active, snapshots contain its information!
(c) In addition to your snapshots, I need the program(s) that cause the unknown vector(s). Snapshots without a program usually cannot be added! So either send me the program (not its complete archive if possible) or tell me where I can download it myself. All the programs will be deleted after examination, so copyrights usually should not interfere with that method.
(d) To find out which programs cause changes in your system, disable all the patches installed in your startup-sequence, user-startup or WBStartup drawer and re-enable them one by one. Each time something new gets started, just have a look at the vector check.

Clears the selected vector (only enabled if applyable to that vector). To clear all task/process fields, select the respective headline. Only use this function if you know what you are doing!

Removes a single element out of a system list. Only use this if you know what you are doing!


The memory monitor has been invented to allow experienced users to snoop around in RAM/ROM and have a look at suspicious vectors (directly from the vector check or by entering the address). It actually is of no use for the average user, so I will not explain it in detail.

Only memory areas from exec's memlist can be monitored, plus Kickstart ROM and RemAPollo's private area. If you reach the start/end of an area, the memory monitor will automatically wrap around to the end/start of that area, so you can never access forbidden or non-existing addresses.

Unfortunately there's one exception from the above rule when running on MorphOS systems with pre-50.58 exec.library: VirusZ cannot determine the real end address of A-Box modules area then and will default to its maximum size. This may lead to some illegal memory accesses towards the end of that memory area, so please avoid monitoring areas around 0x10800000. It's your own responsibility!

The 'Memory Monitor' preferences currently contain the following switches:

'Chip-Ram Start Address = $00000000':
If enabled, the memory monitor overrides the memlist entry for chip ram that usually starts at locations $00000400/$00004000 and allows you to have a look at the CPU's vectortable. This interferes with most debugging tools (eg. MuForce) and will result in lots of annoying hits, so keep this option disabled unless you really need it.

'Display SegTracker Info If Available':
If the SegTracker utility (part of VirusZ's archive) has been installed to your system and this option is enabled, SegTracker's information will be displayed in the status line whenever you monitor a previously tracked memory area.


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